Gas turbine engine with geared turbofan and oil thermal management system
A lubricant supply system for a gas turbine engine has a lubricant lube pump delivering lubricant to an outlet line. The outlet line is split into at least a hot line and into a cool line, with the hot line directed primarily to locations associated with an engine that are not intended to receive cooler lubricant, and the cool line directed through one or more heat exchangers at which lubricant is cooled. The cool line then is routed to a fan drive gear for an associated gas turbine engine. A method and apparatus are disclosed.
1. A lubricant supply system for a gas turbine engine comprising:
a lubricant pump delivering lubricant to an outlet line, said outlet line splitting into at least a hot line and into a cool line, said hot line being directed primarily to locations associated with an engine that are not intended to receive cooler lubricant, and said cool line being directed through one or more heat exchangers at which lubricant is cooled, and said cool line then being routed to a fan drive gear;
at least one of said one or more heat exchangers is a fuel/oil cooler, and said fuel/oil cooler being downstream of a point where said outlet line splits into said at least said hot line and said cool line, such that said hot line is not directed through any of said one or more heat exchangers, and
said cool line supplies lubricant to a journal bearing in the fan drive gear and a portion of the lubricant from said cool line is mixed with said hot line to supply to the locations associated with the engine that are not intended to receive cooler lubricant.
2. A gas turbine engine comprising:
a fan, a compressor section, including a low pressure compressor section and a high pressure compressor section;
a combustor;
a turbine section including both a low pressure turbine section and a high pressure turbine section, and said low pressure turbine section driving said low pressure compressor section, and a fan drive gear provided such that said low pressure turbine section further driving said fan, with said fan and said low pressure compressor section being driven at different rates;
a lubricant system including a lubricant pump delivering lubricant to an outlet line, said outlet line splitting into at least a hot line and into a cool line, said hot line being directed primarily to locations in the gas turbine engine that are not intended to receive cooler lubricant, and said cool line being directed through one or more heat exchangers at which the lubricant is cooled, and said cool line then being routed to said fan drive gear;
at least one of said one or more heat exchangers is a fuel/oil cooler at which the lubricant will be cooled by fuel leading to a combustion section for the gas turbine engine, and said fuel/oil cooler being downstream of a point where said outlet line splits into said at least said hot line and said cool line, such that said hot line is not directed through any of said one or more heat exchangers, and
said cool line supplies lubricant to a journal bearing in said fan drive gear and a portion of the lubricant from said cool line is mixed with said hot line to supply to the locations in the gas turbine engine that are not intended to receive cooler lubricant.
3. A lubricant supply system for a gas turbine engine comprising:
a lubricant pump delivering lubricant to an outlet line, said outlet line splitting into at least a hot line and into a cool line, said hot line being directed primarily to locations associated with an engine that are not intended to receive cooler lubricant, and said cool line being directed through one or more heat exchangers at which lubricant is cooled, and said cool line then being routed to a fan drive gear;
a valve positioned on said cool line, at a location downstream of a point where said hot line splits off from said cool line, and said valve splitting said cool line into two lines, with a first line being directed through said one or more heat exchanger, and a second line being directed through at least one other cooler;
said one or more heat exchanger include a fuel/oil cooler at which the lubricant in the first line will be cooled by fuel leading to a combustion section for the gas turbine engine, and said fuel/oil cooler being downstream of a point where said outlet line splits into said at least said hot line and said cool line, and such that said hot line is not directed through any of said one or more heat exchangers or said at least one other cooler;
a portion of the lubricant from said cool line is mixed with said hot line to supply to the locations associated with an engine that are not intended to receive cooler lubricant; and
said at least one other cooler includes an air-to-oil cooler and also includes an oil-to-oil cooler at which oil from a generator exchanges heat with the oil in said second line.
4. The system as set forth in claim 3 , wherein the lubricant in said hot line does not intermix back into said cool line until a point after said cool line has been routed to a bearing for said fan drive gear.
5. A gas turbine engine comprising:
a fan, a compressor section, including a low pressure compressor section and a high pressure compressor section;
a combustor;
a turbine section including both a low pressure turbine section and a high pressure turbine section, and said low pressure turbine section driving said low pressure compressor section, and a fan drive gear provided such that said low pressure turbine section further driving said fan, with said fan and said low pressure compressor section being driven at different rates;
a lubricant system including a lubricant pump delivering lubricant to an outlet line, said outlet line splitting into at least a hot line and into a cool line, said hot line being directed primarily to locations in the gas turbine engine that are not intended to receive cooler lubricant, and said cool line being directed through one or more heat exchangers at which the lubricant is cooled, and said cool line then being routed to said fan drive gear;
a valve positioned on said cool line, at a location downstream of a point where said hot line splits off from said cool line, and said valve splitting said cool line into two lines, with a first line being directed through said one or more heat exchanger, and a second line being directed through at least one other cooler;
said one or more heat exchanger includes fuel/oil cooler at which the lubricant in the first line will be cooled by fuel leading to a combustion section for the gas turbine engine, and said fuel/oil cooler being downstream of a point where said outlet line splits into said at least said hot line and said cool line, and such that said hot line is not directed through any of said one or more heat exchangers or said at least one other cooler;
a portion of the lubricant from said cool line is mixed with said hot line to supply to the locations in the gas turbine engine that are not intended to receive cooler lubricant; and
said at least one other cooler includes an air-to-oil cooler and an oil-to-oil cooler at which oil from a generator exchanges heat with the oil in said second line.
6. The engine as set forth in claim 5 , wherein the lubricant in said hot line does not intermix back into said cool line until a point after said cool line has been routed to a bearing for said fan drive gear.